Final refuge A Neanderthal-style toolkit found in the frigid far north of Russia's Ural Mountains dates to 33,000 years ago and may mark the last refuge of Neanderthals before they became extinct, according to a new Science study.

Another possibility is that anatomically modern humans crafted the hefty tools using what's known as Mousterian technology associated with Neanderthals, but anthropologists believe that's unlikely.

"We consider it overwhelmingly probable that the Mousterian technology we describe was performed by Neanderthals, and thus that they indeed survived longer, that is until 33,000 years ago, than most other scientists believe," says co-author Professor Emeritus Jan Mangerud of the University of Bergen and the Bjerknes Centre for Climate Research.

Most anthropologists believe modern humans began to replace Neanderthals starting around 75,000 to 50,000 years ago.

Project leader Ludovic Slimak says the study suggests "that Neanderthals did not disappear due to climate shifts or cultural inferiority. It is clear that, showing such adaptability, the Mousterian cultures can no longer be considered as archaic."

Lo-fidelity tool-makers

Slimak, a University of Toulouse le Mirail anthropologist, Mangerud, and their colleagues made the determinations after analysing hundreds of stone artefacts and remains of woolly rhinoceros, reindeer, musk ox, brown bear, wolf and polar fox unearthed at a site called Byzovaya in the western foothills of the Polar Urals.

Dates were obtained for sand at the site as well as for some of the bones, many of which "have cut marks that indicate processing by humans," according to the researchers.

The tools attributed to the Neanderthal's Mousterian style (named after the site of Le Moustier in southern France, where they were first identified) were mostly flakes, which the scientists recreated by banging a hard hammer on select stones.

It's therefore likely that the original creators of the tools used a similar manufacturing method. The preserved flakes could have been used to make two-sided scrapers, perhaps for hunting, removing meat from bones, or working with animal hides.

Modern human tool-crafting methods associated with the Upper Paleolithic (between 40,000 and 10,000 years ago), on the other hand, "were generally focused on the production of what we call blade or bladelet technologies," Slimak said. The Byzovaya hominins did not apparently make such "blades," which were often crafted from organic materials like bone and ivory. So Slimak's team argues that Neanderthals likely made the Byzovaya tools.

Population pressures

Even though Neanderthals may have disappeared from other locations throughout Europe and Asia, Slimak argues they likely persisted in this remote area near the Arctic Circle. Since conditions in the region were harsh even then, Slimak believes only strong individuals existing in a well-ordered, savvy group could have survived there.

The Neanderthals may have been gradually absorbed into the population of anatomically modern humans via interbreeding and replacement. As Mangerud explains, "Probably modern humans ousted the Neanderthals."

Slimak likens this to what happened to earlier populations from the Americas.

"In a bit more than 500 years, what will remain of the traditional native societies in America? Just imagine what will remain of these impressive cultures, or their territories, during the next millennium," he says.

Recently another study concluded that Neanderthals might have died out earlier than thought and not interacted much with our species, but Neanderthal expert Professor Erik Trinkaus believes that study "says nothing about possible late Neanderthals in the periphery of cul-de-sacs of western and northern Europe," and therefore does not discount this latest finding.

Trinkaus of Washington University in St Louis, thinks the Neanderthal-attributed tools from Russia are "very interesting in terms of people being that far north during the Middle Paleolithic."